Acetylene making and heavy oil coking process



July 12, 1960 S. P. DICKENS ACETYLENE MAKING AND HEAVY OIL COKING PROCESS Filed March 11, 1957 MAKING AND HEAVY on. COK'ING rnocnss Samuel P. Dickens, Poughkeepsie, N.Y., assignor to Texaco Inc., a corporation of Delaware Filed Mar. 11, 1953s. No. 645,062 6Claims. c1.zos-ss ACETYLENE This invention relates to a process for generating acetylene by reacting calcium carbide with water, and

moreparticularly to such process wherein the contacting is conducted in. a medium of heavy hydrocarbon oil to provide, in addition to acetylene, a coking feedstock containingsuspended lime. A further aspect ofthis mvention is a unitary process for producing acetylene and petroleum coke containing occluded lime.

The uses of acetylene are widespread, for example in the welding and cutting of steeland in the production of rubber-like polymers, acrylonitrile, calcium cyanamide, etc. Petroleum coke containing occluded lime can be used, for example, in blast furnaces toprovide fuel and flux and can, for example, after suitable conditioning to drive off volatile matter and to form the resulting carbonquicklime product into suitable shapes, be used to make additional calcium carbide or a specialty slagging furnace fuel for admixture with other fuels.

Broadly, in a process for generating acetylene fromcalcium carbide and .making hydrated lime as a 'byproduct my improvement comprises contacting calcium carbide particles with water and a mobile reaction me- A dium of oil coking charge stock; The charge stock is a heavy hydrocarbon oil such as a heavy 'or reduced crude, vacuum bottoms, residue from thermalcrack1ng hydrocarbon residua, or mixtures thereof. 'A- suitable coking chargestock will have an initial boilingpoint of 600 to 1000 F. and preferably about. 700 to 800; F.,

and API gravity of 0 to'20 and preferably about .8 .to

15.9, and a Conradson', carbon residueofbetwcen 5, and j 40- weight percent and preferablyabout -10- to 25%- (ASTM Test D-180-52). The car ide sizgsupaniqulafly useful in the practice of my process are the iiner ones,-

e.g /g. by ,4 Rice, and 14 .ND.

Because of the presence of the oilvehiclein the liy dra- 0 tion of the carbide the normallyviolent reaction, '2

r CaC +2H O- Ca(OH) +C I-I is tempered for easy control. Preferably, the contacting is done by adding the carbideto a vigorously agitated mixture of water and oil, the oil-water mixture having 1 the characteristics of a dispersion or emuls on of di'screte water particles in the oil. The quantity of Water need not be as high in proportion to the carbide used as is conventionally practiced in the so-called wet process because the heat generated is readily taken up as sensible heat in the oil medium. Temperature of the acetylene generation should not be substantially greaterthan 300 F. to suppress obnoxious by-products and acetylene polymerization, and the generation is advantageously conducted ata temperature from 100-200 F. to keep the oil highly mobile. I prefer to usea quantity of water in the water-oil mixture which is from about one to four times the stoichiometric amount necessary for completely decomposing the calcium carbide being added plus attendant water vapor losses from the reaction mixture,

which losses can amount to about 2% to about 10% or nuclei.

more of the stoichiometric water used depending on the operating temperature and pressure.

The ratio of oil to water used can be broadly from about 1:1 to about 50:1 or more oil-to-water by weight;-

land locked refineries.

after in a particular coking operation. 1

Thus my process can be carried in a pressure coking operation wherein both a clean and a dirty oil are recycled to the coke drum, or in a delayed coking operation where only the dirty oil is recycled to the coke drum. It cancontain finely-divided carbon residue from previous cracking or distillation operations, WhlChIESld-HC actually assists in emulsifying or stabilizingv thewater-oil 1 mixture for the. carbide treatment in my process. If desiredone also can add to the oil a very minor amount, e.g., .0.1-1% based on the weight of the oil, of a cheap. emulsifier such .as tall oil .soap, alkali metal sulfonatesf and, sodium oleate, or a mixture of same, butthese are not required. Foam, if encountered, can be controlled by addition of a defoamingagent such as dialkyl, diaryl,

or alkyl-aryl silicone polymer, e.g., a dimethyl silicone polymer having viscosity of -l000 centistokes at 25 C. added to, the mixture in concentration of 50-.-2O0

p.p.m. My process is not an impregnation of the carbide with the oil, but rather a direct contacting of the carbide with discrete water particles in a mobile reaction medium ofthe heavy hydrocarbon oil.

ter and oil are brought as an emulsion'into the carbide Advantageously the wacontacting zone, but, of course, can be added as separate streams. p h

My acetylene generating step is advantageously. integrated with acoking process as, for example, a fluid j coking'process or a coking process wherein coke accumulates in a static bed, e.g delayed coking or pressure coke stilling (also called coking plus thermal cracking).

A fluidized coking system such as the one described in U.S.P. 2,725,349 can be modified to inject coking charge stock containing hydrated lime from the acetylene generation into the oil feed inlet of the coking zone'. 1

Seeding need not be practiced in my operation, however, because the lime ordinarily furnished adequate coking Advantageously, the turbulent fluidized bed of such coking zone is maintained at about 850-1000 P.

so that no calcium hydroxide is converted into calcium oxide with the liberation of water which would increase greatly the vapor velocity in the coker. In the burner section of such fluidized coking system some or all of the calcium hydroxide can be converted into calcium oxide using temperatures above about 1100 R, if desired. The burning can be done with air, oxygen-enriched air, or substantially pure oxygen.

The drawing is a schematic diagram showing my unitary process of acetylene generating and petroleum coking...

wherein a delayed coking step is used. Condensers, coolers, pumps, reflux equipment and such auxiliary equipment is not shown, but will be installed in conventional fashion as is necessary or desired.

Patented? ran 12, 1960.1

as a dirty oil and represents a disposal problem in many, It can be fractionated, however, into a clean and a dirty portion, and either or both parts used in my acetylene generating process and there.- f

Into emulsion contactor 10 one charges water through line 11 and coking;

oil, a heavy residual petroleum fraction. optionally containing a' minute amount or a'n einulsifier, through line 13. The water and oil' are mixed and maintained in the intimate suspension by mechanical agitation while calcium carbide particles are fed throug h line 9, .Wet raw'acet- 6 yl e n'e "gas; famed rge'd from the contacts through line 12 for purification and other handling. in i i n e T O er t on. n be ade c91 tinu s b'yj using a 'seriesfo f emulsion contactors, one i A fl' aul Wh EWW Q' I i i line. g n fiifi l A tmat lv; on nt di 'e wl ivr ite one 'contactor into another and so on su'ccessively to provide suine em time of'conta'ct for utilizing: substantially;

K t in ho ver; he o acting.

fromfcolging drum 13 through line 719' andrpass edinto frac'tinnal d illing tower (ffractionatofi) Z11 Fracs1 thecoke, stillivapors'finto gas to t a s I distillates overhead fractions, (withdrawnihriough line 22 and"1ow e r points)? was heayy'gas'bil fractionfwithdrawn through line2'3l sa e i heayy'gas oilissent'through, line 24'forcooling as 51 balance is sent through line rarer mixr'g, e. stock" to heater 16.: Theratio .oftrecycled gasijoil' toj' f're sh feed is; between about 1 and aboujtflljdf bbls /bbl." This heavy gas OiYisscharacteriZedlSy 2010:- 25" ARI. gravity, a carbon"residue'less fthan opsfiweig ei percent andfa 90% ASTM Ib'ofilin'gj point f: easin car is permittedtobuildlup,indium 18 for-a period of s; y 1 t the'aforesaidtemperature andpr" sure. At the. end of"tir'ne, tliefoily' lime-contain g feedjandiheayy gasoil can be'switch'ed mothered; g drurm, not shown: 1T'lie accumulated 'T ke and occludedlimein'drunrIllS-is teama'a ab O to i5fp.s by adr'nis'sion of about 370"Ffstea m to drive ofi lincqlied residualyoil, .whichiissalso removedtth rough lin e19w I The ntainingcalcifimlliydroiide iswithdrawn se of the mag rnr'rLthrough manhole 29- "The cokehnie calcined,- if desired, to 'remoye moisture andyolatile matter, usually, atia temper til i of 1890 100 FLorhigh'er. Preferably"the ca1cined=prod-' not is. d'rnto a conventional calc umv carbide produc tion operationiusing a cqnvemionariectric furnace, an-

IndliQtiQll furnaceor'a shaft furnace. (Operations ofithe tama e 0 parts 0i.- cokingroil,charge stock, a2. red gge Crude hydrocarbon o oil having; ARI gravitya' his"? 24.2 Co'nrads'on carbon residue content of-3.5%, and SUS viscosity at F. of 459, and 26 parts of water was agitated to, form an" emulsion. The emulsion was dropped slowly on to 35.2 parts of granulated commercialcalcium carbide maintained in an atmospheric pressure vessel. Acetylene was given off as a result of the contacting, and hydrated lime by-product was formed. Temperature of the operatitirfmew-100 F.

:fI hehydrated lime bearin oily mixture remaining at the are rifar'facetyfene' ge condh'etedas outlined above, can be passed into a cokifig vessel wherein it is maintainedat a backpressure of '125 psz'iag. "and; temperature ofi 850- Fffo1 about- 12- hours. At the end of this time the resu-lting coke is steamedtoleaye a residue of about 114 parts, "thisbeing amiiitfire-o'f about 40 parts of carbon occluding abdut5741riarts=dfic'alcium hydroxide.

I claim:

1. In a process for generating acetylene from calcium 2. The process of-lclangr 1" whereintlie'quantity of water er iuf rm n ea 'd sp rs qn sl With n: he an e. o oneto ou t mes h st h ometr c'amu t ne essary rcolnpletelydecomposing the calcium carbide plus attend ant water vapor losses: from thereaction mixture.

'3 The process-10f claim l w-herein said'dispersion con tains an emulsifier selectedfrom the groupTconsisting oftallf 'l soap, alkalirnetal' sulfona'te and sed-iunr oleategsaid ulsifir'being present'in' an amount of from aboutf n Wi n e ange ofr m b 0- Q'p s1 yweightof oil per parti of water,-thereby forming awet acetylene: gas; phase: and a; liquid: phase containing sus pended hydrated-lime,separately withdrawing said gas-1 phase and' said liquidphase from; saidhydration zone? sasgiag a t 'le' a'st a portio'ri of- 'sai di liquid phase-contain 3 suspendedlime into a coking zone niaintainetl at' tempe f tur' between about SSOFahd ab6tit1500" FQ; thereby forminghydrocarbon dist ate? an coke con? ttaining 'oc cludedlinr s'aid'c'oking zone saidhydr'ocarb containing occluded lime; U

5. The process ofi claim 4 wher comprises'abody'oif colseparticles V a A 'aden e tl f t' fliledl e t em era ure 9. e 1100 i y it i e nsa s iqe in 9 1 re e 'm i faf i n e a .t r e i prem s qrmis a mime. sup ns oa 9f, wa r -ahewwil-the eti. Q -Q i-t ate n v di s en:

sion being-withinthe rane of;fron about-1 to 50 parts by; weight o f; oil per; part of water; bringing-said suspension. into contact'with:calciunr carbide particles in a re ing acetyleneand"-said"las na'med mixture [fronifsaid reaction zone: i

(References ob -following page) distillate' a n d said" petroleum coke "aintamed in the form a References Cited in the file of this patent UNITED STATES PATENTS Green May 1, 1900 Herber May 16, 1916 White May 15, 1917 Ferguson Nov. 25, 1924 Riggs Nov. 19, 1940 6 Cahn et a1 Nov. 29, 1955 Kirkpatrick et a1. Feb. 24, 1959 FOREIGN PATENTS Great Britain Nov. 12, 1898 Great Britain June 10, 1899 Great Britain Sept. 22, 1910 

4. A UNITARY PROCESS FOR PRODUCING ACETYLENE AND PETROLEUM COKE WHICH COMPRISES ADMIXING, AT A TEMPERATURE FROM 100-230*F. IN AN AGITATED HYDRATION ZONE, CALCIUM CARBIDE PARTICLES WITH A SEPARATELY FORMED DISPERSION OF WATER PARTICLES IN A MOBILE REACTION MEDIUM OF OIL COKING CHARGE STOCK, THE RATIO OF OIL TO WATER IN SAID DISPERSION BEING WITHIN THE RANGE OF FROM ABOUT 1 TO 50 PARTS BY WEIGHT OF OIL PER PART OF WATER, THEREBY FORMING A WET ACETYLENE GAS PHASE AND A LIQUID PHASE CONTAINING SUSPENDED HYDRATED LIME, SEPARATELY WITHDRAWING SAID GAS PHASE AND SAID LIQUID PHASE FROM SAID HYDRATION ZONE, PASSING AT LEAST A PORTION OF SAID LIQUID PHASE CNTAINING SUSPENDED LIME INTO A COKING ZONE MAINTAINED AT TEMPERATURE BETWEEN ABOUT 850* AND ABOUT 1500*F., THEREBY FORMING HYDROCARBON DISTILLATE AND PETROLEUM COKE CONTAINING OCCLUDED LIME, AND WITHDRAWING FROM SAID COKING ZONE SAID HYDROCARBON DISTILLATE AND SAID PETROLEUM COKE CONTAINING OCCLUDED LIME. 